Abstract

We evaluate the theoretical performance of a point-source
integrating-cavity absorption meter (PSICAM) with Monte Carlo
simulations and a sensitivity analysis. We quantify the scattering
errors, verifying that they are negligible for most ocean optics
applications. Although the PSICAM detector response is highly
sensitive to the value of the wall reflectivity, the absorption of an
unknown fluid can be accurately determined with a PSICAM if appropriate
reference solution(s) are chosen. We also quantify the error
that results if the source is not perfectly isotropic, finding that
moderate amounts of source anisotropy can be tolerated provided that
the detector is properly located with respect to the source.

Percentage error in the PSICAM detector response as a
function of detector location for anisotropic light sources. The
detector position is given by angle θd with
respect to the forward direction of the source. The source angular
distribution is the Henyey–Greenstein function with asymmetry factors
g = 0, 0.2, and 0.5. The results shown are for
a = 0.3 m-1, b = 0.7
m-1, r = 0.05 m, and ρ = 0.99.